Model-Based Approaches in Developing an Advanced Aftertreatment System: An Overview

Cummins has recently launched next-generation aftertreatment technology, the Single Module^TM aftertreatment system, for medium-duty and heavy-duty engines used in on-highway and off-highway applications. Besides meeting EPA 2010+ and Euro VI regulations, the Single Module^TM aftertreatment system offers 60% volume and 40% weight reductions compared to current aftertreatment systems. In this work, we present model-based approaches that were systematically adopted in the design and development of the Cummins Single Module^TM aftertreatment system. Particularly, a variety of analytical and experimental component-level and system-level validation tools have been used to optimize DOC, DPF, SCR/ASC, as well as the DEF decomposition device. The highlights of this work can be summarized as follows: a). internal dosing is more efficient than external dosing to control HC slip; High CPSI DOCs show better HC oxidation performance at high SV due to enhanced mass transfer; b). the adopted advanced DPF technologies enable greater ash capacity for long maintenance intervals; c). SCR performance was optimized with the use of a hydrothermally robust Cu-Zeolite catalyst coated on high CPSI substrates.